GYROSCOPE ROTOR VOLTAGE HOLDING CIRCUIT FOR UNEXPECTED POWER SUPPLY REMOVAL

A MEMS gyroscope includes driving circuitry applying a time-varying forcing-signal to its driving mass through capacitive couplings and readout circuitry determining angular rotation of the gyroscope rate based on changes in capacitive couplings between signal sensing stators and the sensing mass. A charge pump powered by a supply-voltage generates a charge pump output-signal. A decoupling capacitance is connected to a rotor pad. Sensing circuitry asserts a control-signal when the supply-voltage is greater than a threshold-voltage and the gyroscope is set in a powered-on condition, but deasserts the control-signal when the supply-voltage is less than the threshold-voltage or a power-down command is sent to the system. Switch circuitry couples the charge pump output-signal to the decoupling capacitance so that a DC bias-voltage is formed across the decoupling capacitance when the control-signal is asserted but decouples the charge pump output-signal from the decoupling capacitance when the control-signal is deasserted.